Wiring 4 group 27 in parallel

[mel s]

Originally Posted by dennis45

This should be what you are looking for.

dennis45
Trojan 27tmh batteries are 12 volt ....(NOT 6 volt) batteries.
27TMH, Flooded Battery, 12V, 115Ah @ 20Hr, Group 27, Wingnut Terminal, Trojan Battery Company
Mel
'96 Safari

[crockwood]

Hahaha, thanks for your reply stick. I only put in 1 battery because the wiring and the tray is a PITA. . The other 3 I just set in the tray. The battery arrangements are LF. RF. LR. RR.. it had the flag type terminals before that were always a problem to remove. And the battery tray doesn't extend very far. Difficult to remove batteries. So, that's why I went to the small jumpers I attached with wing nuts. Chris

[wa8yxm]

Bad choice, Shouold have gone with T-105s.

But that said..

Best connection is a heavy brass or copper bus bar with 5 lugs
One or each battery and the 5th runs to the fuse/breaker and disconnect switch. Same length leads to the positive,

Same length leads to the ground point, I would like to see multiple ground connections (at least 2) very close to each other (Within an inch)

However unless you have a LARGE iverter (over 999 watts) you can just jumper all 4 Positives one to the other daisy chain style, and then off to the RV
and on the negative side do the same thign, only come off a different battery,, I would choose batteries #2 and 3 as the take off points.

[crockwood]

Wa8xym, thanks for your reply. Yeah, I wanted to go with the T 105's they are too tall for the enclosure. Plus the battery tray would not work. I still might have the battery tray modified so battery tray moves out further. And my inverter is a XANTREX 458 2500 watts with 130 amp charger.

So, on the bus bar. Each battery has a lead to negative, and on the other each has a lead to positive? Now the wiring is criss cross on each battery positive and negative on separate batteries. That's the way it was from Gillig. But, they used 1 cable for each positive and negative that had flag terminals, a real PITA to remove. Chris

[TQ60]

Simple statement is all positives tie together and all negatives tie together.

Buss barr or jumpers all depends on what you want.

If posts like auto battery or bolts like storage battery.

They DO NOT NEED TO BE SAME LENGTH as this is dc not rf.

The wires just need to be able to carry the current and have good connections.

Send some photos.

[crockwood]

Tq60, thanks for your reply. Don't think the bus bar solution will work. That would be 4 wires running to either side. Would work if batteries were in a line. I already have the Trimetric and the inverter and other stuff in the battery compartment.

Best case scenario is I want 1 cable for positive and 1 cable for negative with eyelets so I can use wing nuts on the batteries. Can't find this.. chris

[TQ60]

Look in the phone book for battery shops then welding supply.

Most can custom make cables and usually charge just for materials.

Great if you can drive it there and let them look and suggest options.

If you have new wires and they are long enough they can be cut and new ends.

Many many ways to do this and it sll depends on how you want to do it.

If you have screw posts then best option is short post to post wires so any battery can be removed.

Cable should be large enough to carry full load.

Cable to load and ground can be connected where handy...it is suggested to connect opposite corners if possible but it really does not matter much if good work is done.

Be sure to use grease on all connections as well as working it into the area where the connector is attached to the cable.

[mel s]

Originally Posted by TQ60

Look in the phone book for battery shops then welding supply.

Most can custom make cables and usually charge just for materials.

Great if you can drive it there and let them look and suggest options.

If you have new wires and they are long enough they can be cut and new ends.

Many many ways to do this and it sll depends on how you want to do it.

If you have screw posts then best option is short post to post wires so any battery can be removed.

Cables should be large enough to carry full load.

Cable to load and ground can be connected where handy...it is suggested to connect opposite corners if possible but it really does not matter much if good work is done.

Be sure to use grease on all connections as well as working it into the area where the connector is attached to the cable.

TQ60

The correct parallel wiring of 4 12V batteries is that simple.

[twinboat]

Ok, get 1 cable from front bat + to inverter, 1 cable from rear bat + to inverter.

Jump front right bat + to front left batt + with another short cable, do the same on the rear. Try turning some batteties around to get better cable runs.

With the neg side do the same thing, but go to the shunt with them.

Once thats done, pick a + terminal to put your other positive cables on, or run them to the inverter too.

The grounds should all run to the far side of the shunt.

Last thing gather up all the wing nuts and throw them to watch them fly. Go get nuts that you can tighten up with a wrench.

If you need cables made, go to a truck parts store and ask where they can be made, or some marine parts stores make them.

Good luck

[rjxj]

As Ray,in posted the 12 volt pic. Do it that way.

You may even want to buy one of these, 16 Ton 11 Dies Hydraulic Wire Crimper Crimping Tool Battery Cable Lug Terminal | eBay yes it's cheap but you are not going into manufacturing cables. You can do all the jumpers on the bench and even reach into the tighter areas with the crimper. The dies will be half arse marked but it's easy to hold them on the terminal end and figure out which one to use. Do a couple test crimps to get the hang of it. Your buddies can then borrow it and reciprocate with beer. It's silly easy after you try it. The 10 ton would probably be strong enough too. Dont crank the nuts down as tight as you would on a bolt, you are dealing with lead posts.

Some guys like to use heat shrink on the terminal end, some go by the theory of leaving it exposed for cleaning. I like to grease the wire strands thoroughly then crimp, then grease the terminal, then heat shrink. Try the heat shrink for size as you may need to slip them onto the cable first before putting the terminal on. Just keep the batteries rinsed off on a regular schedule and you wont have corrosion.

Use nuts instead of wings. Wrap your wrench with electrical tape or slide a piece of shrink wrap onto an old wrench and keep it for battery and tight electrical compartment use. Everyone drops a wrench at some time.

Yes, I already know that you disconnect the negative first when servicing electrical systems but all the melted wrenches and battery explosions I have witnessed have happened from guys dropping or contacting batt neg & pos ON the battery. It happens. Make the wrench non conductive, your eyeballs will love you.

Find a auto parts store that sells individual terminals. Not all auto parts stores deal in this stuff. Be sure they are copper.

[crockwood]

Twinboat, thank for your reply. Ok, so tie bat pos 1&2 and wire to positive post. And 3&4 same thing. And negative same thing except the cables to the ground side of shunt. . Correct? Thank you, chris

[twinboat]

Yes,
All neg battery cables to 1 side of shunt, ground and neg inverter to other side. That way shunt reads amps in and out of house batteries.

[twinboat]

One thing we forgot to mention, the positive cables should be going to a 350 amp fuse, then the inverter.

[TQ60]

Use stainless steel hardware ONLY.

Get a 1/4 drive torque wrench from harbor freight...make sure it reads close enough then be sure to torque everything correct.

Major miss I have seen with battery plants are wrong hardware...bolts too short and not engaging enough threads and too loose in fear of stripping them.

if you have studs then just use nuts ans star split washers with lots of grease...nor a glob but use an acid or chip brush and paint everything well then after complete touch up to insure good coating.

Also forgot to mention fuse like I usually do.

Many sources for those but try to locate a good heavy duty kit that has large connection point so it can be used as a junction point.

Cable (s) to battery one side and cable to mh other.

While you are at it run a piece of quad wire (cheap 4 conductor 18 to 26 ga) from fuse holter to dash or monitor panel.

Also pull #10 to supply optional power if you wish.

The quad has connection to both sides of fuse with a 1/2 amp fuse between wire and fuse.

3rd wire to batt neg and 4th to chasis ground.

At other end you can use female banana jacks or other interface to allow easy access for measuring voltage, confirming fuse status and ground connections all from inside.

You could locate a panel mount meter and some switches and make a nice looking meter panel too.

If doing that add connections to input and output of inverter to have some Prevost style stuff...

Darn it adding to my to do list now...